Chosen Solution

Yesterday the shift stop to work most of the time (works 1/100) suddenly (did not spill anything) And weird thing that today the Control Option keys joined the party and they stop working (only left keys) It’s a MacBook Pro “Core i7” 2.2 15" Mid-2015 (IG) (MJLQ2LL/A). I have tried the keys in my Windows VMWare and they don’t work. In keyboard viewer in Mac they are not highlighted when tapped.

  1. How to know for sure this is a hardware issue ? 2) Why the first day just the shift is not working and the next day other keys ? 3) if it’s a hardware issue how to fix it ? Can it be an issue not in just keyboard but more serious ? 4) how much it coast to fix it ?

I would reseat the keyboard connector as show in step#33 of this guide: MacBook Pro 15" Retina Display Mid 2015 Upper Case Assembly Replacement